Flexible bags for the storage, heat treatment of and dispensing of colostrum to bovine calves are known. One bag is described in detail in U.S. Pat. No. 8,336,495 issued on Dec. 25, 2012 to the present inventor. Various nipple assemblies and mounting tools that can be used with flexible storage bags is described in U.S. Pat. No. 8,408,408 issued on Apr. 2, 2013 to the present inventor. A method of feeding a calf using a flexible storage bag is described in U.S. Pat. No. 8,490,577 issued on Jul. 23, 2013 also to the present inventor. U.S. Pat. No. 9,357,798 issued on Jun. 7, 2016 again to the present inventor and describes vessel, which can comprise a flexible bag, in combination with a cap or closure that indicates to a user when the contents of the vessel remote from the vessel's walls have reached a predetermined temperature. All four of the foregoing patents are incorporated herein by reference for the teachings contained therein.
The flexible bags are typically used to store colostrum that has been expressed from cows that have just given birth to a calf or calves. The colostrum is stored in the bags which can be immediately heat-treated or refrigerated or frozen to preserve the valuable contents. The colostrum is heat-treated in a specialized pasteurizer between predetermined minimum and maximum temperatures, frozen or refrigerated for storage and removed from storage and warmed prior to use. The bag and its contents might then have special accessories attached to the bag which allow the operator to feed a calf directly from the bag as covered in U.S. Pat. No. 8,408,408. Maintaining a narrow temperature band is critical especially during pasteurization. Depending on the configuration of the bag and its contents, the colostrum proximate the outside of the bag is heated more quickly to the desired temperature than the contents closer to the center of the bag farthest away in distance from the bag walls. Without being able to maintain a proper configuration, and in order to heat the centermost contents to the desired temperature in a time efficient manner, the colostrum closest the bag walls may inadvertently be heated to a temperature higher than the predetermined maximum temperature. Higher temperatures can cause degradation of the desirable properties of the colostrum, and as such, heating the colostrum to a temperature exceeding the maximum temperature is to be avoided as much as is possible.
Sometimes it is necessary to access small amounts of colostrum stored in a storage bag, such as for a sample for testing or a very small amount necessary for a feeding. Further, on occasion, it is necessary to add small amounts of medicine or a reagent to a bag before, during or after pasteurization. In anyone of these instances, removal of a cap on the spout is necessary to gain access. This can be messy, and destroys any safety seal that may be present on the spout making it more difficult to later assess whether the contents of the bag have been improperly accessed thereafter. Perhaps most importantly, the opening of the cap subjects the contents to atmosphere potentially compromising sterility and potentially contaminating the bag's contents.